knight



(No Model.) 2 Sheets-Sheet 1.

E. M. KNIGHT.

FILTER.

No. 569,382. Patented 001;. 13, 1896.

WHZ/VESSES k IJVVENTOR zww Was-W 6. M Attorney v THE NO cuwa wsnwawn a c 2 Sheets-Sheet 2 (No Model.)

B. M. KNIGHT.

FILTER.

1 a/cen'ted 001;. 13, 1896.

WIZNESSJJS UNITED STATES EDIVARD M. KNIGHT,

SPECIFICATION forming part of Letters FILTER.

OF NEIV YORK, N. Y.

Patent No. 569,382, dated October 13, 1896.

Application filed June 24, 1895. Renewed March 7, 1896. Serial No, 582,276- (No model.)

T0 whom, it may concern:

Be it known that I, EDWARD M. KNIGHT, acitizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Filters; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Figures 1 and 1 are vertical sectional views of two of the many forms of filters to which my invention may be applied. Fig. 2 is a perspective view, partially broken away, of a rectangular filter-frame. Fig. 3 illustrates a plan view of a circularfilter-bed and its frame. Fig. 4 is an enlarged detail showing a portion of the filter-frame, the woven-wire backing and its surrounding frame, and the asbestos sheet exterior thereof and broken away to expose the backing and its surrounding binding or frame. Fig. 5 is a modification to be referred to.

My present invention is closely identified with the inventions disclosed in my former applications, filed May at, 1895, and May 15, 1895, Serial Nos. 548,096 and 549,420, respectively,as it relates to the same forms of filters; and my invention consists of the parts and constructions and combinations of parts which I shall hereinafter fully describe and claim.

In carrying out my present invention I may use any of the forms of filters shown in the drawings or any other well-known form of filter, whether designed for lateral filtration and with either a square or rectangular filterbed frame or a circular filter-bed frame or for a vertical filtration with either the square or rectangular or circular frames.

In Fig. 1 the unfiltered-water vessel A is of any suitable form, material, and capacity. It may have an inlet a with a valve 17 controlled by a float c, the inflow from the pipe a falling upon a directing-plate (I, so that it will flow down gently and without splash, which might unduly disturb the water. In the lower portion of the vessel A, or connected with the same, if desired, is the filteredwater chamber B, which is provided with any of the well-known forms of faucets or draw-offs.

In the form of filter shown in Fig. 1 the water is filtered laterally through a bed which stands vertically; and as the present improvements relate wholly to the filter-bed and its frame I will now proceed to minutely describe them.

In the former patents and in the several forms of filters heretofore made by me asbestos cloth was used as a filter-bed. The outer raw edges of this cloth were turned over the frame, or a binding-strip in some instances, and were presented toward the inside of the filter and into the filtered water, in coutradistinction to being presented outwardly or toward the unfiltered water. This construction, which was necessary because of the forms of filter-frames used, I have found, after extensive manufacture and experiment, possesses certain objections, which are due wholly to the form of the frame, the securing of the cloth, and the direction in which the edges of the cloth were presented. The raw edges being turned toward the inside of the filter and being in what I might term the filterchamber, they were always being washed off by the flow of water through the bed, which is usually supplied with charcoal of paste form, and commingled with the filtered water, so that when the filtered water was drawn for drinking purposes it was charged with minute floating specks, which were, in fact, small fibers or parts of threads of asbestos. The presence of'these particles not only impaired the appearance of the filtered water, but they were also objectionable and more or less dangerous from a sanitary standpoint, since being essentially insoluble and indigestible theirpresence in the stomach was to be avoided. I

In said previous constructions made by me the filter-frames were of such forms that I was practically compelled to turn the raw edges of the asbestos fabric into the filtered water, which resulted in the water washing away small portions of the edges, as before described; and it has not been until the present time that I have been able to devise a frame which enables me to turn these heretofore unprotected raw edges outside of the filtered-water chamber, so that the flow of water would not cause them to wash off or disintegrate and be carried with the purified water into the filtered-water chamber. In addition to this the new frame herein shown and described enables me to tightly stretch the fabric over the frame, so that when the charcoal paste, which I prefer to apply to the surface of the asbestos, is in place there is no danger of its cracking and flaking off by reason of the sagging of the fabric when in use, and to maintain a tight joint by keeping the ends of the fabric out, and so dispose of the ends of the woven wire that a very close joint is formed and maintained. The setting of the wire cloth in a frame as I now disclose, and then sewing the asbestos cloth to it, makes a simple method of permanently securing the cloth in a tight condition, and facilitates the turning of the cloth outward without danger of its slacking or lessening its tension and the disposing of the raw edges exterior of the frame, so that it is impossible for particles of the fibers to be washed off and permitted to mingle with the water that is filtered.

In order that the present invention may be fully understood, I will now minutely describe what I believe is the preferred form of filter bed and frame.

The filter-bed frame is formed of an suitable material, and preferably contains an interior supporting-frame D, open on two of its sides and provided with horizontal and vertical bars or plates, as in said former application, which are perforated for the free passage of water, the said filter-bed frame surrounding the supporting-frame and having a surrounding outwardly-turned flange 10 at its opposite sides. Against the outer face of this flange is placed the reticulated plate or sheet of woven wire 12, whose outer edges on all of its sides are soldered or otherwise secured to the inner face of a surrounding plate or strip 13, or, if preferred, these edges may be bound by a U-shaped strip, as in my said former application, Serial No. 549,420. The fiat plate or strip 13 shown in the drawings is formed or provided with holes 14, and the sheet or piece of asbestos is laid against the outer face of the woven-wire or reticulated plate with its edges projecting beyond the same, and is permanently secured to the said plate after being properly stretched by sewing through it and through the holes 14 of said plate. hen the asbestos sheet is thus placed in position and permanently secured under tension by 'sewin g, or by the use of rivets orother fastenings, if desired, passed through it and the holes 14, the outer edges of the flange 10 and the outer raw edges of the asbestos sheet are then readilyturned outwardly, in contradistinction to inwardly, as in the former constructions. Now the purpose of this will be obvious. When the raw edges of the fabric are turned outwardly, and this is easily accomplished when the cloth is held by sewing water in passing through the cloth has no other effect upon these raw edges than to force them against the main portion of the cloth. This prevents any of the fibers or particles of these raw edges from being washed off and carried along with the water into the filtered-water compartment, and at the same time the action of the water upon these raw edges will result in driving the fibers thereof against the face of the asbestos sheet at the point where they will greatly assist in making a water-tight joint around the turnedover edge of the flange 10. The raw edges of the fabric being thus turned toward the inflowing water rather than away from the same, as in the old forms, cannot have its fibers or particles worn away and caused to mingle with the filtered water, as before described, thereby overcoming this great objection to these forms of otherwise useful filters.

In bending the flange 10 and the raw edges of the fabric over onto the body portion of the fabric and clamping the flange tightly upon the fabric the fabric is also forced into the holes 14 in the plate, which is secured to the reticulated or woven wire backing, whereby it is more securely held under its proper tension and without danger of it slacking to loosen the charcoal-paste.

The filter-frame may be held in its vertical position by means of a hollow tube 15, passing through the frame and perforated for the passage of the filtered water to the filteredwater chamber, and this tube may carry at its lower end a packing 16, which is designed to be seated tightly upon the outlet 17, in a manner substantially as shown and described in my said former application, Serial No. 549,420, or it may be held to said outlet and stayed or braced at its upper end, as shown in the said application, or in any other wellknown manner. The unfiltered-water vessel may contain but one of these filter-frames and attachments or there may be two or more, placed side by side.

In the form of filter shown in Figs. 1 and 3 a circular or round frame is used and intended for vertical filtration, although it is obvious that such vertical filtration may occur through a square or rectangular filterframe horizontally placed.

For vertical filtration the filtered water vessel should preferably contain a ledge or shoulder 16, upon which the filter-frame rests; but in other respects the filter-frame is like the one before described, except that the flange is circular instead of having straight sides and that the interior supporting-frameand the attachments for holding a verticallydisposed frame in position will not be necessary; also, if desired, the flange 10 of the filter-frame may be turned straight out and a separate clamping-piece employed to bind it and the edges of the asbestos and soldered to the main part of the frame without departing from the spirit of my invention.

Fig. 5 is a modification. In this figure the ICC plate 13 is bent along the line of the stitching-holes, and the asbestos is clamped as before described.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A filter-frame consisting, essentially, of a reticulated or woven-wire backing, a sheet or piece of fabric laid upon the same with its raw edges turned outwardly and folded upon the outer face of the fabric, and a surrounding-strip for binding edges of the backing and turned-over portion of the fabric.

2. A filter-frame consisting, essentially, of a reticulated or woven-wire backing, a plate or strip surrounding the same and secured to the edges thereof, said surrounding plate or strip having apertures made through it, and a sheet of fabric laid over the outer face of the backing and stitched to the plate or strip through the holes therein said fabric having its raw edges folded toward the outer face of the fabric, and down upon the same, and means for clamping the turned-over portion of the fabric and exterior edge of the surrounding plate or strip.

3. A filter-frame having a filter-bed composed, essentially, of a sheet of fabric through which the water is filtered said fabric having its raw edges folded outwardly and down upon the exterior face of the fabric so that they may be presented toward the water to be filtered.

4. A filter-frame consisting, essentially, of a foraminous backing the outer edges of which are secured to a surrounding plate or strip having openings made through it, a sheet of asbestos placed over said backing, means whereby the fabric is secured to the surrounding plate or strip through the openings in the same, and a clamping frame or strip folded over the edges of the surrounding apertured plate or strip and the raw edges of the fabric.

5. A filter-frame consisting of an exterior frame having outwardly-extending flanges, a foraminous plate or backing laid upon said flanges, and having its edges secured to a plate or strip having a series of openings made through it, a sheet of asbestos placed over the exterior face of the foraminous plate or backing with its raw edges projecting beyond the surrounding apertured plate or strip, said projecting flange adapted to be folded outwardly whereby the raw edges of the fabric are folded outside of and against. the outer face of the fabric so as to be presented toward the water passing through the fabric, and an interior supporting-frame for the filter-bed.

In testimony whereof I affix my signature in presence of two witnesses. v

EDWVARD M. KNIGHT.

Witnesses:

T. WALTER FOWLER, CHAPMAN W. FOWLER. 

